Mining stocks were leading the fallers on Friday on the back of a slump in commodity prices and concerns over a slowdown in China. Iron ore prices were headed for their sixth consecutive monthly decline, the longest losing streak on record, due to rising supplies from Australia and Brazil.Iron ore prices have declined by around 9% this month, with the value of the commodity having now fallen every month since December. This is the longest string of monthly losses since data from The Steel Index Ltd began in November 2008, according to Bloomberg. Investors were also showing caution ahead a batch of economic data from top metals user China next week, including figures which are expected to show that manufacturing growth weakened in May.Chris Beauchamp, Market Analyst at IG, said that this will "contradict recent signs of improvement in the economy" and provides "an excuse for some selling in raw materials".The prices of other metals such as gold and silver were also in the red in afternoon trade.Weak industrial production figures in Japan overnight and an unexpected dip in consumer spending in the States is also likely to have had an impact on sentiment on Friday.Diversified mining heavyweights Anglo American, BHP Billiton and Rio Tinto were among the worst performers this afternoon, each trading around 3% lower. Fresnillo, Antofagasta and Randgold were also lower. In another hit to the mining industry, polymer products firm Fenner issued a profit warning. The group, which makes conveyor belts for the mining industry, said annual profits would be 10-15% below market expectations on the back of weakness in the US coal market.Meanwhile, solid fuel supplier and logistics group Hargreaves Services also fell after saying results from its Production Division will be below expectations this year due to "challenging trading conditions" in coke markets and delays.Top performing sectors so far todayHealth Care Equipment & Services 5,817.12 +1.98%Technology Hardware & Equipment 1,120.95 +1.17%Beverages 14,549.98 +0.95%Electronic & Electrical Equipment 4,172.79 +0.84%Software & Computer Services 1,200.87 +0.78%Bottom performing sectors so far todayIndustrial Metals & Mining 1,246.83 -2.52%Mining 16,500.09 -2.30%Industrial Transportation 3,006.64 -1.26%Forestry & Paper 11,568.44 -0.83%Construction & Materials 4,407.51 -0.31%BC